Neuropsychiatric phenotypes of anti-NMDAR encephalitis: a prospective study

The relevance of anti-N-methyl-D-aspartate receptor encephalitis for psychiatrists

Psychiatrists are often the first to be consulted in patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. While this disease is rare, psychiatrists need to be aware of its relevant fundamental, clinical and therapeutic aspects. We begin by reviewing the connection between anti-NMDAR encephalitis and the glutamate hypothesis of schizophrenia. Next, we focus on the profile of the patient typically afflicted with this disease. Then, we tackle the limited utility of current diagnostic criteria during the early stage of the disease. After reviewing the psychiatric features, we debate the quest for finding specific psychiatric phenotypes that could facilitate early-stage diagnosis. We conclude by discussing the treatment of psychiatric symptoms and disease outcomes. As follows, this paper presents the relevance of anti-NMDAR encephalitis for psychiatrists.

Case report: Anti N-methyl-D-aspartate autoimmune encephalitis following a mildly symptomatic COVID-19 infection in an adolescent male

Background

Antibodies against N-methyl-D-aspartate receptors are the most commonly identified cause of autoimmune encephalitis. While predominantly associated with malignancies, cases of anti-N-methyl-D-aspartate receptor autoimmune encephalitis have been reported after infections with the herpes-simplex virus or, more recently, in patients with severe COVID-19 disease.

Case presentation

A previously healthy 17-year-old male adolescent acutely developed psychosis with auditory and visual hallucinations, fluctuating mental status, and an isolated seizure 5 weeks after a mildly symptomatic COVID-19 infection. The symptoms continued to worsen, accompanied by catatonia, and additional neurological symptoms developed during the initial antipsychotic treatment. A diagnostic workup revealed antibodies against N-methyl-D-aspartate receptors in the cerebrospinal fluid without other major abnormalities. After establishing the diagnosis, initiation of immunomodulatory therapy stopped the symptom progression and led to full recovery within 2 months.

Conclusion

The case is remarkable in that anti-N-methyl-D-aspartate receptor autoimmune encephalitis developed shortly after a COVID-19 infection in an adolescent, despite the individual experiencing only mild COVID symptoms. The diagnosis should be considered in cases of acute-onset psychotic symptoms during or after COVID-19 infection, particularly in individuals without a prior psychiatric history, who present with atypical psychiatric or neurological features.

The Neuropsychiatric Side of Cerebral Venous Thrombosis: A Case of Delirium and Catatonia

We report a patient with cerebral venous thrombosis who initially presented with psychosis and who then progressed to delirium and catatonia within a few days. Upon treatment and resolution of the thrombosis, she presented complete remission of the psychiatric disturbances. This case highlights a specific neuropsychiatric presentation of cerebral venous thrombosis involving psychosis, catatonia, and delirium, which, to our best knowledge, has not been reported in the neurological or psychiatric literature. However, it reminds us of mental status and behavioral abnormalities which are not infrequent features of cerebral venous thrombosis. This leads to a discussion regarding the psychopathology, etiology, and pathophysiology of the case.

Suicidal Thoughts and Behaviors in Anti-NMDA Receptor Encephalitis: Psychopathological Features and Clinical Outcomes

OBJECTIVE

A wide variety of neuropsychiatric symptoms are described during the acute phase of anti-N-methyl-d-aspartate receptor encephalitis (ANMDARE), including psychosis, mania, depression, and catatonia, but there are few reports on suicidal thought and behaviors in ANMDARE. To address this gap in the literature, the authors measured the presence of suicidal thoughts and behaviors among a large cohort of Mexican patients diagnosed with definite ANMDARE.

METHODS

This observational and longitudinal study included patients with definite ANMDARE hospitalized at the National Institute of Neurology and Neurosurgery of Mexico between 2014 and 2021. Suicidal thoughts and behaviors were assessed before and after treatment by means of a clinical interview with relatives and a direct clinical assessment with each patient. Thoughts of engaging in suicide-related behavior and acts of suicidal and nonsuicidal self-directed violence before and during hospitalization were recorded.

RESULTS

From a total sample of 120 patients who fulfilled the diagnostic criteria for definite ANMDARE, 15 patients (13%) had suicidal thoughts and behaviors during the acute phase of the disease. All 15 of these patients experienced psychosis and had suicidal ideation with intention. Three patients engaged in preparatory behaviors and seven carried out suicidal self-directed violence. Psychotic depression and impulsivity were more frequent among those patients with suicidal thoughts and behaviors than among those without any form of suicidality. Four patients engaged in self-directed violence during hospitalization. Remission was sustained in 14 of 15 patients, with suicidal ideation and self-directed violence persisting during follow-up in only one patient.

CONCLUSIONS

Suicidal thoughts and behaviors are not uncommon during the acute phase of ANMDARE. On the basis of our sample, the persistence of these features after immunotherapy is rare but may be observed. A targeted assessment of suicidal risk should be strongly considered in this population.

Psychiatric features in NMDAR and LGI1 antibody-associated autoimmune encephalitis

Patients with autoimmune encephalitis (AE) often developed psychiatric features during the disease course. Many studies focused on the psychiatric characteristic in anti-NMDAR encephalitis (NMDAR-E), but anti-LGI1 encephalitis (LGI1-E) had received less attention regarding the analysis of psychiatric features, and no study compared psychiatric characteristic between these two groups. The clinical data of AE patients (62 NMDAR-E and 20 LGI1-E) who developed psychiatric symptoms were analyzed in this study. In NMDAR-E, the most common higher-level feature was "behavior changes" (60/62, 96.8%) and the lower-level feature "incoherent speech" was observed in 33 patients (33/62, 53.2%), followed by "agitation" (29/62, 46.8%) and "incongruent laughter/crying" (20/62, 32.3%). Similar to NMDAR-E, "behavior changes" was most common in LGI1-E (17/20, 85.0%), but the features of suicidality, eating, and obsessive-compulsive were not reported. The top three lower-level features were visual hallucinations (9/20, 45.0%), incoherent speech (8/20, 40.0%), and mood instability (7/20, 35.0%). The comparative study found that "incongruent laughter/crying", in lower-level features, was more frequently observed in NMDAR-E (32.3% vs. 0%, p = 0.002). Moreover, the Bush Francis Catatonia Rating Scale (BFCRS) assessing the catatonic symptoms in NMDAR-E were higher than LGI1-E, but the 18 item-Brief Psychiatric Rating Scale (BPRS-18) showed no difference in the two groups. In summary, both NMDAR-E and LGI1-E often developed psychiatric symptoms. In contrast with LGI1-E, the psychiatric feature "incongruent laughter/crying" was more frequently associated with NMDAR-E, and catatonic symptoms were more severe in NMDAR-E.